Verity Audio Montsalvat DAC/PRE D/A processor Measurements

Sidebar 3: Measurements

I measured the Verity Audio Montsalvat DAC/PRE with my Audio Precision SYS2722 system (see the January 2008 "As We See It"), repeating some tests with the magazine's Audio Precision APx555 system. Apple's USB Prober utility identified the Verity as "Combo384 Amanero" from "Amanero Technologies" with the serial number string "413-001." The Verity's USB port operated in the optimal isochronous asynchronous mode, and Apple's AudioMIDI utility revealed that the DAC/PRE accepted 32-bit integer data sampled at all rates from 44.1kHz to 384kHz. The AES/EBU and coaxial S/PDIF inputs accepted 16- and 24-bit data sampled at rates up to 192kHz.

The DAC/PRE's output level at 1kHz in DAC mode was 3.43V from the balanced outputs, 2.1V from the single-ended outputs. In Preamp mode, the output with the volume control set to "0.0 dB" was the same as it was in DAC mode, but the maximum output level was now 13.28V, balanced, and 8.17V, unbalanced. With the Polarity button set to "+," both outputs preserved absolute polarity (ie, were noninverting) in both modes. The single-ended output impedance was less than 1 ohm at all audio frequencies. In contrast, the balanced output impedance was a very high 3.9k ohms at 20Hz and 1kHz, dropping slightly to 3.7k ohms at 20kHz. This would not have been a problem with the Parasound amplifiers I use for my auditioning, however, which have a very high input impedance.

The Verity offers a single reconstruction filter for 44.1kHz PCM data, which, as shown in fig.1, is a conventional linear-phase filter with symmetrical ringing before and after the single full-scale sample. This filter's ultrasonic rolloff with 44.1kHz data (fig.2, magenta and red traces) reaches full stop-band attenuation at 24kHz, a little above half the sample rate (vertical green line). The aliased image at 25kHz of a full-scale tone at 19.1kHz (cyan, blue) is suppressed by 120dB, and the harmonics associated with the 19.1kHz tone are all very low in level.


Fig.1 Verity DAC/PRE, impulse response (one sample at 0dBFS, 44.1kHz sampling, 4ms time window).


Fig.2 Verity DAC/PRE, wideband spectrum of white noise at –4dBFS (left channel red, right magenta) and 19.1kHz tone at 0dBFS (left blue, right cyan) into 100k ohms with data sampled at 44.1kHz (20dB/vertical div.).

Fig.3 shows the frequency response with data sampled at 44.1, 96, and 192kHz. The output is down by 0.5dB at the top of the audioband at all three sample rates, with the smooth ultrasonic rolloff interrupted by a steep rolloff just below half the sample rate with 96kHz and 192kHz data. Channel separation was superb, at >125dB in both directions below 1kHz, decreasing to a still superb 113dB at 20kHz. The DAC/PRE's noise floor was free from any power supply-related spuriae (fig.4).


Fig.3 Verity DAC/PRE, frequency response at –12dBFS into 100k ohms with data sampled at: 44.1kHz (left channel green, right gray), 96kHz (left cyan, right magenta), and 192kHz (left blue, right red) (1dB/vertical div.).


Fig.4 Fig.4 Verity DAC/PRE, spectrum with noise and spuriae of dithered 1kHz tone at 0dBFS with 24-bit data (left channel blue, right red) (20dB/ vertical div.).

An increase in bit depth from 16 to 24, with dithered data representing a 1kHz tone at –90dBFS, dropped the Verity's noise floor by around 27dB (fig.5). This implies a resolution of >20 bits, which is among the highest I have encountered. When I played undithered data representing a tone at exactly –90.31dBFS, the waveform was symmetrical, with negligible DC offset and the three DC voltage levels described by the data free from noise (fig.6). With undithered 24-bit data (fig.7), the DAC/PRE's very low analog noise floor means it can output a clean sinewave, even at this very low signal level. Linearity error with 24-bit data (not shown) was very low down to below –120dBFS.


Fig.5 Verity DAC/PRE, DAC mode pre-repair, spectrum with noise and spuriae of dithered 1kHz tone at –90dBFS with: 16-bit data (left channel cyan, right magenta), 24-bit data (left blue, right red) (20dB/vertical div.).


Fig.6 Verity DAC/PRE, waveform of undithered 1kHz sinewave at –90.31dBFS, 16-bit data (left channel blue, right red).


Fig.7 Verity DAC/PRE, waveform of undithered 1kHz sinewave at –90.31dBFS, 24-bit data (left channel blue, right red).

All the previous measurements were taken with the Verity in DAC mode before the intermittent fault that I mention in the review text raised its head. When I received the repaired DAC/PRE back from Verity, I repeated some of the testing. However, the results in DAC mode were not as good as they had been before the repair. Fig.8, for example, repeats the spectral analysis taken with a dithered 16- and 24-bit 1kHz tone at –90dBFS. Compared with the spectra in fig.5, the 24-bit noise floor (blue and red traces) has risen by around 6dB and the spectrum of the tone now has a pair of low-frequency sidebands visible around each of the harmonic frequencies. Switching the Verity to Preamp mode with the volume control set to "0.0dB" and repeating this test gave the same excellent result shown in fig.5. I therefore continued the testing of the repaired DAC/PRE in Preamp mode with the volume control set to "0.0dB."


Fig.8 Verity DAC/PRE, DAC mode post-repair, spectrum with noise and spuriae of dithered 1kHz tone at –90dBFS with: 16-bit data (left channel cyan, right magenta), 24-bit data (left blue, right red) (20dB/vertical div.).

In this mode, the DAC/PRE produced very low levels of harmonic distortion with full-scale data (fig.9). The third harmonic is the highest in level, at just –120dB (0.0001%), and all other harmonics are even lower in level. This spectrum was taken into the high 100k ohms load. When I reduced the load impedance to the punishing 600 ohms, the levels of the harmonics didn't rise. Intermodulation distortion in Preamp mode with an equal mix of 19 and 20kHz tones, each lying at –6dBFS, was similarly very low (fig.10), with the difference tone at 1kHz lying at –124dB (0.00006%).


Fig.9 Verity DAC/PRE, 24-bit data, spectrum of 50Hz sinewave, DC–1kHz, at 0dBFS into 100k ohms (left channel blue, right red; linear frequency scale).


Fig.10 Verity DAC/PRE, HF intermodulation spectrum, DC–30kHz, 19+20kHz at 0dBFS into 100k ohms, 24-bit, 44.1kHz data (left channel blue, right red; linear frequency scale).

I examined the DAC/PRE's rejection of word-clock jitter via its USB, AES/EBU, and S/PDIF inputs. Fig.11 shows the spectrum of the DAC/PRE's output when it was fed high-level, AES/EBU 16-bit J-Test data. All the odd-order harmonics of the undithered low-frequency, LSB-level squarewave lie at the correct levels, indicated by the sloping green line, but some closely spaced sidebands can be seen surrounding these harmonics. There is also a trio of spurious tones visible between 9kHz and 10kHz, though these are low in level. These tones can be seen more clearly with 24-bit USB data (fig.12).


Fig.11 Verity DAC/PRE, high-resolution jitter spectrum of analog output signal, 11.025kHz at –6dBFS, sampled at 44.1kHz with LSB toggled at 229Hz: 16-bit AES/EBU data (left channel blue, right red). Center frequency of trace, 11.025kHz; frequency range, ±3.5kHz.


Fig.12 Verity DAC/PRE, high-resolution jitter spectrum of analog output signal, 11.025kHz at –6dBFS, sampled at 44.1kHz with LSB toggled at 229Hz: 24-bit USB data sourced from MacBook Pro (left channel blue, right red). Center frequency of trace, 11.025kHz; frequency range, ±3.5kHz.

I shall assume that the less-than-superb performance I experienced in DAC mode was specific to this much-traveled sample. But in Preamp mode, Verity's DAC/PRE joins that small group of D/A processors that offers close-to–state-of-the-art resolution, joining Benchmark's DAC3, Chord's DAVE, exaSound's s88, HoloAudio's May, MBL's N31, Okto Research's dac8 Stereo, and the Weiss DAC502.—John Atkinson

Verity Audio
US distributor: High Fidelity Services
2 Keith Way, Suite 4
Hingham, MA 02043
(781) 987-3434

Long-time listener's picture

Wow! A $25,000 DAC that keeps breaking, and after it's sent back for repair it doesn't measure the same. I've gotta go out and get me one of those!

Umm, maybe not. Maybe I'll just stick with my $700 Topping D90SE, the best-measuring DAC on the planet, which also has a pre-amp function. Cheers

MhtLion's picture

Just a personal opinon. To my knowledge, ESS 9018 chip is among the easier to work with DACs. ESS 9038 Pro, on the other hand, is known to require a lot more experience working with a DAC. The fact they got a lower noise floor - I think Verity surely knows how to engineer good audio equipment. But, the fact there were those issues and that they are using the old 9018 chip - Verity's experience with a DAC may fall short compared to other companies like Okto. What I'm really trying to say is that the high price may have nothing to do with the engineering pedigree of the designer behind it. Electrical engineering is a vast field. The fact an engineer knows how to design an analog preamp/power amp may or may not have much to do with how to work with a DAC. An engineer who worked on high-end audio for 30 years may know shit compared to a recent PhD graduate when it comes to DAC. Also, some high-end audio companies do not even have a single person with the proper engineering background. I'm not saying at all that Verity is one of those companies, but I'm saying that the high cost may attribute to quality material used and an awesome-looking case, and perhaps extensive outsourcing of various processes, which sometimes include the designing of the core architecture itself. I believe a $25,000 DAC/Pre must sound good to many ears, but I also believe people may get the same or even better fulfilling experience with a $2,000 DAC nowadays because DAC is relatively a new field.

Axiom05's picture

Someone making and selling a $25K component doesn't know how to solder. Probably the worst advertisement that they could have.

John Atkinson's picture
Axiom05 wrote:
Someone making and selling a $25K component doesn't know how to solder.

Surface-mount components are not hand-soldered. Instead, the populated printed-circuit board is flow-soldered in one pass by machine, most likely at a subcontractor's facility. Generally, soldered boards are then soak-tested to find "infant mortalities" and the survivors proceed to assembly.

A failure of a solder joint this late in use is rare but not unknown.

John Atkinson
Technical Editor, Stereophile

Axiom05's picture

Whatever the exact process is it certainly does not inspire confidence. Maybe this is just an unfortunate one-off but the fact that the "fixed" unit still had issues with measurements is, again, not confidence inducing. I certainly do appreciate the detail with which you described the whole process. Everyone can make up their own minds.

Anton's picture

This brings to mind a famous Hi Fi axiom:

If that thing functioned any worse, it would cost 90,000 dollars. (Got that one from my wife, she said it about a pair of speakers she heard at CES back in the day.)


That being said, JVS could hear a problem, which puts him ahead of some reviews of broken gear that were pretty glowing.

Kudos to JVS, who aim was true!

tonykaz's picture


This thing is a prototype that you lads are Beta Testing for them.

Tony in Venice Florida

Axiom05's picture

S/N 001, yes, very amusing.

John Atkinson's picture
tonykaz wrote:
This thing is a prototype that you lads are Beta Testing for them.

I asked Verity, who assured me that this sample was from the first production batch.

John Atkinson
Technical Editor, Stereophile

tonykaz's picture

it probably is the first production unit, first of 10 ? ( maybe )

I'm not trying for sarcasm or anger nor am I anxious about any of this.

I think that Stereophile was wonderfully generous to help a promising venture get a bit of traction.

The Company and designers work hard to get a working product out to Dealers. I continue to be proud of Stereophile for helping or trying to help.

Good on All'yall.

Tony in Venice Florida

ps. those Abyss lads seem to approve of the Sonic Quality of Apple's New MQA Streaming. Abyss approving of Streaming is say'n a whole lot !! isn't it?

jmsent's picture

.....where did you come up with that?

tonykaz's picture

Mr.J.Austin reports about Industry in this most recent 'Print' Issue of Stereophile. This happened to be revealed by Apple, last month!

Apple iTunes is now 100% high resolution with MQA and a few other important bits. Apple MP3 is lonnnnnnggggggg gone .

I noticed that the Owners of JPS: the manufacturer of the AB1266 Abyss headphones ( and Diana ) did a YouTube comparison between Tidal and the New iTunes Apple MQA with Apple iTunes now surpassing the previous Streaming leader. ( who isn't surprised ?? )

RIAA now reports Streaming dominates the Music Formats $ Pie with 83% of all collected Format monies. ( in USA ).
Physical ( CD & 33.3 ) split 50/50 about 6% of the format $ Pie.

I did not come up with that! Mr.JA2 did!

Brace yourself, here it comes, it's real .

Tony in Venice Florida

Axiom05's picture

Are you confusing ATMOS with MQA?

tonykaz's picture

I did not observe the Apple Event

and certainly, I could've extrapolated in error.

Overall, Apple promises higher performance from iTunes which should result in all of us changing to some extent.

I feel certain that Stereophile's Editors will be pounding out abundant responses to the Apple changes.

Tony in Venice Florida

jmsent's picture

Perhaps this is just you playing "fast and loose" with terminology? MQA is a very specific encoding scheme (that has been discussed to death in these pages and elsewhere) that delivers a folded and compressed digital file in a FLAC envelope. Apple has never even used fact, they've never supplied MP3 audio either. It's been out for a while that Apple, along with Spotify, will now offer lossless streaming, with Apple adding to this Spatial Audio, and Dolby Atmos files . It's all explained here: My question is specifically about Apple adopting "MQA". I don't see it mentioned anywhere in the Apple news releases, or anywhere else, for that matter.

tonykaz's picture

Once again,

this is mentioned in the Editor's Industrial Report , in the Stereophile Print Magazine that arrived around July 6th, 2021.

additionally, the ABYSS design team discuss the Apple Streaming with the unfolding of MQA.

At this point, Confusion and perhaps Shock abounds.

Still, I am not inventing any of this although Mr.Austin reporting could be inaccurate.

Time will tell.

I'm watching as is Everyone else.

Tony in Venice Florida

Archimago's picture

Don't know what this is about Apple and MQA. Apple Music lossless is streaming with ALAC, and as far as I've heard, no MQA in the Apple data unless somehow that's the only version available (might have to watch out for labels that are strong proponents like 2L).

Note that MQA encoding can be distributed with ALAC, any lossless compression will do, not just FLAC.

Apple is putting quite a bit of press into "Spatial Audio" however which is a lossy EAC3-Atmos stream that can be decoded with virtualization into "3D" headphone playback or multichannel streaming with the Apple TV (and to some extent MacOS Big Sur) to your receiver as discussed recently on my blog.

Isn't Abyss a headphone manufacturer? What do they have to do with Apple Music?

tonykaz's picture

Mr. Joe and his two Sons do manufacture the Abyss 1266 headphone and the Diana headphone. They have a YouTube Channel ( like Shiit and others ). In May of this year they discussion-analized and reviewed the New Apple iTunes system.

So, Jim Austin and the Abyss lads are my two sources of info.

I will continue to monitor these Streaming developments but will not be a Manufacturing participant in any Audio related products.

I'm just a curious bystander.

Tony in Venice Florida

ps. I consider Mr.Jim Austin our leading authority on this matter. ( so far )

Jim Austin's picture

No MQA at Apple Music.

Jim Austin, Editor

tonykaz's picture

Still, everyone wins big.

Apple streaming high-res lets regular citizens see a benefit from higher performance Audio Gear, even in their Cars and at no extra $ subscription cost .

Stereophile's Subscription Base should increase by measurable percentages as Citizens look for reliable advice on better Gear & Music Reviewing.

I got the MQA wrong but I'm in no way sorry about this long overdue development.

What took so dam long?

Tony in Venice Florida

Jim Austin's picture

... and I've talked to Apple people about this (with no real resolution): How do you get Apple Music into your hifi? Airplay 2 is a poor choice due to sample-rate limitations. For now, Apple insists on using its own software platform (Apple Music) for accessing the stream, which many will refused to do (preferring Roon, etc), and which only runs on a full-function computer and can't be controlled remotely (or not conveniently). Plus, it's worrying that Apple is downplaying the significance of the move to lossless, choosing instead to emphasize the more dramatic contrast of Dolby Atmos (which as implemented is lossy).

Pluses and minuses.

Jim Austin, Editor

tonykaz's picture

Thank you for peering into this development.

I feel that we all have good reason to be pleased that the lower resolution formats are finally being obsoleted.

Personal Audio Players are amazing , Music is increasingly available at reasonable prices, Transducers are continuing to improve.

It seems a month hasn't gone by without someone raising the Sound Quality Bar another notch.

Stereophile remains the informative Portal into all these exciting things. Each month brings another series of interesting Audio Industry reads to my Mail Box!

Thank You,

Tony in Venice Florida

Mark’s toys's picture

I have immense respect for the Verity owners, they build heirloom quality loudspeakers.

But taking in a buddy with some knowledge of electronics and putting your name on that product takes some nerve. So Verity all of a sudden want’s to play amplification, digital with the Bentley’s of the upper crust audio world? They are up there with their loudspeakers no question. But their line of electronics does not have the maturity and pedigree to play at those price levels. And kilobuck high-end digital machines should be QUADRUPLE tested to avoid embarrassment. All the more if you are sending a product in for a review! Here’s an idea. Stick to speakers, to what you know best, boys, please.

PeterG's picture

It's a shame that the reviewer's full disclosure on a manufacturing issue with a single item seems to have prevented many commenters from a holistic understanding. It's silly to hold this against Verity in a purchase decision. Paradoxically, maybe less disclosure or less discussion of the issue/resolution would have been better?

Jim Austin's picture

Everyone is free to draw their own conclusions--as you have done here.

Best Wishes,

Jim Austin, Editor

Anton's picture

When I see something like this, I do admit to wondering…..

When did it get broken? Did the factory fail to adequately check out an item of this price before they shipped?

If it were mine, would I simply tell reviewers to ship a piece of gear of this magnitude along to the next reviewer so casually? “It was shipped many times to many people” doesn’t seem to exemplify an eye for detail, either. It seems to me that a Stereophile review might be a big deal. I’d have my local dealer make sure delivery and set up were done properly. If a manufacturer can’t get a fully intact unit to Stereophile, then good luck to consumers buying serial #2-10.

MauriceRon's picture

many good points made in this review of the very expensiv veriti amp & yet most comenters have chosen to get obsessive over a broken solder joint that could've easily been causes by a careless courier worker...

canonken's picture

Not a defense of this piece, but when I read this I thought back a few issues (do not recall the exact brand, model) to a speaker I believe had an improper part or construction in the crossover which caused a noticeable but not immediately obvious issue in the sound. That example, along with this are scary as unless you really knew what you were hearing, should hear, or especially measure might just think that was the sound, and you trusted it.

I do applaud Stereophile calling these issues out, if they wanted to just suck up to the industry they would conveniently forget to mention it in the review.

This is a good example of the importance of not only having good engineering and QC, but also knowing how to build things that can stand up to shipping and years of real world use. Think of brands like Bryston, McIntosh, Pass Labs that have a reputation for consistent, reliable performance. That is worth a lot for the average person who buys something and keeps it.